跨平台开源桌面GIS软件的设计与实现

GIS软件开源可有效促进GIS软件技术的发展,这也是GIS技术发展的趋势之一。目前,国内还没有跨平台的专业桌面GIS开源软件。本文研究并实现了跨平台的开源桌面GIS软件-SuperMap iDesktop Cross,采用C++语言实现了GIS功能内核,同时基于OSGi框架,采用Java语言实现了用户界面开发。该软件具备数据管理、数据处理、三维可视化、空间分析等GIS功能,同时提供应用程序编程接口（API）,支持定制开发。这将使专业桌面GIS软件广泛应用于包括Linux在内的更广泛的操作系统,使更多的人参与到GIS软件技术的发展中来,共同推动国产GIS软件技术的发展。     

针对无人机倾斜摄影数据的不同处理软件空三加密

以山西省右玉县杀虎口古长城为例,采用Trimble UX5 HP搭载Sony A7r相机完成数据采集,利用Context Capture软件和PhotoMesh软件进行三维重建,并利用Geomagics软件对三维模型进行精细处理,比较两种软件的空三精度,得出Context Capture软件的空三精度更高。同时利用外业实测检查点对模型进行精度计算,得到Context Capture软件的模型精度,其点位中误差为0.192 m,表明这种方法可以满足实景三维建立模型的要求,为智慧城市的建设提供了强有力的数据保障。     

GeoNat v1.0: A dataset for natural feature mapping with artificial intelligence and supervised learning

Machine learning allows “the machine” to deduce the complex and sometimes unrecognized rules governing spatial systems, particularly topographic mapping, by exposing it to the end product. Often, the obstacle to this approach is the acquisition of many good and labeled training examples of the desired result. Such is the case with most types of natural features. To address such limitations, this research introduces GeoNat v1.0, a natural feature dataset, used to support artificial intelligence‐based mapping and automated detection of natural features under a supervised learning paradigm. The dataset was created by randomly selecting points from the U.S. Geological Survey’s Geographic Names Information System and includes approximately 200 examples each of 10 classes of natural features. Resulting data were tested in an object‐detection problem using a region‐based convolutional neural network. The object‐detection tests resulted in a 62% mean average precision as baseline results. Major challenges in developing training data in the geospatial domain, such as scale and geographical representativeness, are addressed in this article. We hope that the resulting dataset will be useful for a variety of applications and shed light on training data collection and labeling in the geospatial artificial intelligence domain.     

一种VGI矢量数据增量变化发现的多层次蔓延匹配算法

目的 矢量要素的匹配是发现地物要素变化的重要方法之一,高精度的匹配结果有助于更快地发现变化地物,进行更新。VGI矢量数据具有几何和语义信息丰富的特点,但使用传统的矢量要素匹配算法难以发挥VGI矢量数据的优势。以城市 VGI道路数据为研究内容,提出基于多层次蔓延的矢量要素匹配算法,将 VGI数据和专业测绘数据进行匹配对比,从而实现道路变化增量信息的快速识别。     

Metadata and provenance for spatial analysis: the case of spatial weights

Within a CyberGIS environment, the development of effective mechanisms to encode metadata for spatial analytical methods and to track the provenance of operations is a key requirement. Spatial weights are a fundamental element in a wide range of spatial analysis methods that deal with testing for and estimating models with spatial autocorrelation. They form the link between the data structure in a GIS and the spatial analysis methods. Over time, the number of formats for spatial weights implemented in software has proliferated, without any standard or easy interoperability. In this paper, we propose a flexible format that provides a way to ensure interoperability within a cyberinfrastructure environment. We illustrate the format with an application of a spatial weights web service, which is part of an evolving spatial analytical workbench. We describe an approach to embed provenance in spatial weights structures and illustrate the performance of the web service by means of a number of small experiments.     

低空无人机平台应用于海滩地形监测的初步研究

消费级无人机的普及使得海滩监测有新的选择,但不同无人机平台的监测精度与适用情景各异,有必要进行适用性评价。本研究利用两种无人机平台（精灵4 RTK、经纬M300 RTK）与两种地形监测技术（SFM摄影测量、激光雷达）在象山县大沙海滩进行海滩地形监测,计算低空无人机监测海滩地形的平面误差与高程误差,分析不同无人机平台准同步监测结果之间的差异及其原因;利用无人机监测结果分析大沙海滩的地形特征,讨论海滩地形冬季前后变化。分析结果显示,无人机平台能胜任高精度的海滩地形变化监测工作。     

黄河三角洲地面沉降影响因素综合分析

黄河三角洲形成时代新、厚度大的第四纪松散地层为地面沉降提供了物质基础。构造运动、沉积物固结和海平面运动等自然因素对沉降的影响由来已久。近几十年日益加剧的地下水和油气的大量开采及大规模工程建筑等人类活动成为沉降新的触发因素,多种因素的叠加作用使沉降时空分异规律和形成机理复杂化。本文基于水准监测及相关背景资料,分析了人类活动集中区广饶县和东营区的沉降特征,综合比对各种人为和自然沉降诱因,发现黄河三角洲地下水超采、工程建筑、油气开采、构造运动、沉积物自然固结和海平面上升等因素对地面沉降的年均贡献比约为28：4：2：3：2：1,人类活动对地面沉降起主导作用。     

新时代防震减灾科普宣传优化策略研究

本文汇总近年来全国及安徽省防震减灾科普宣传开展情况及其效果,结合未来经济社会和技术发展的趋势,通过多种形式的调查研究并结合传播学的相关理论进行分析,提出新时代防震减灾科普宣传优化策略。      

Precise orbit determination of the Haiyang 2C altimetry satellite using attitude modeling

GPS Solutions - The precise satellite clock bias prediction is critical in improving the positioning, navigation and timing (PNT) service capabilities of the global navigation satellite system...     

The semi-diurnal cycle of deep convective systems over Eastern China and its surrounding seas in summer based on an automatic tracking algorithm

Climate Dynamics - Deep convective systems (DCSs) are associated with severe weather events and can affect regional and global climate. To study the semi-diurnal variation of DCSs over Eastern...